Tube mill



Sept. 29, 1931. A. w.V cA-TLIN 1,825,333

' TUBE .MILL

Filed Sept. 27, 1930 2 Smets-Sheet 1 Fig. l.

lnvenl'or.

www. @um www fmwfj ATyS.

Sept. 29, 1931. A. w. cA'rLlN TUBE MILL Filed Sept: 27, 1930 2 Sheets-Sheet 2 ATTyS.

Patented Sept. 29, 1931 PATENT oFF-'ICE ARTI-IUE W. CATLIN, OF CHICAGO, ILLINOIS, ASSIG-NOR TO BRADLEY PULVEBIZEB COMPANY, F ALLENTOWN, PENNSYLVANIA, A CORPORATION OF MASSACHUSETTS TUBE MILL Application inea september 27, 1930. serial No. 484,885.

This invention relates to improvements in v tube mills of the type comprising a drum having means Jfor introducing the material to be ground at one end, and means for discharging the ground material #from the drum at the other end, grinding members, such as balls, pebbles, rods, etc., being lprovidedL within the drum to aid in the pulverizing operation.

y In usual constructions the ground material is treated by a classifier or separator to remove the material ground to a predetermined degree ot lineness, and the tailings are returned to the inlet end of the mill where they 5 are re-ground. Any considerable quantity of these relatively fine tailings will cushion the action of the grinding bodies and, therefore, delay the grinding action.

The present invention relates to improve- :o ments in mills of the type described which comprise the provision oi' means for returning the tailings to the grinding mill at any desired position longitudinally of the drum, so that the cushioning effect of the tailings j :c5 vupon the coarser mate ial, during the initial grinding operation, will be avoided and the Arapidity ot the grinding action will, theretore, be accelerated.

The invention may also be employed for iso the purpose of introducing into the mill a substance ot another character than that which is fed into the mill, such, Jfor example, as the addition of gypsum to the clinker being pulverized during the production of 1:5 Portland cement.

The invention may be employed for introducing material, such as tailings, or other suitable material, at a predetermined distance from the inletend of a tube mill having 4.0 a single grinding compartment, but is espeiirst or initial grinding compartment, so that the tailings, or such other material will be mixed with the original material of substantially the same degree of lineness, or of the ne degree of hardness, or grindability.

Any suitable means may be provided for delivering the tailings, or other material, to the drum or any compartment thereof. Preferably, however, such means comprises a tubular conduit extending into the drum through one or both of the hollow trunnions upon which the drum is mounted, with means 'or causing the material to travel lengthwise oi the conduit, and suitable ports having gates selectively operable to cause the material to be delivered into the drum, or to a selected compartment thereof at a predetermined distance trom its inlet or outlet end.

In accordance with the present invention the conveyer or conduit may extend into the drum through either or both of the tubular trunnions thereof, and suitable means, such as a screw, may be employed for causing the tailings, or other material, to travel through the conduit. Desirably the conduit may be so connected to the drum as to rotate therewith and provided with a spiral screw or plate rigidly secured within the conduit and having a proper pitch to cause the material to travel longitudinally of the conduit during its rotation with the drum.

Preferred embodiments of the invention are illustrated in the accompanying drawings, in which,

Fig. l illustrates, mainly in longitudinal vertical section, a single compartment tube mill and provided with an air separator, with means for returning the tailings from the separator to the conveyor which delivers the same to the drum at any one of a plurality of selected positions longitudinally of the drum;

Fig. 2 is transverse sectional view of the tubular conduit on line 2-2, Fig. l;

Fig. 3 is a transverse sectional view ot a modified form ot armored tubular conduit;

Fig. 4 is a view showing mainly in longidinal section a tube mill having a series of grinding compartments, and also illustrating an air separator together with means for returning the tailings through the outlet end of the grinding mill to any selected compartment at any predetermined distance from the inlet end oi' such compartment; and,

Fig. 5 is a longitudinal sectional view oi"Y grinding mill illustrating means for introducing tailings, or other material, into the mill at any desired distance from the inlet end thereof through a conveyer extending through the tubular trunnion forming the inlet through which the material is ted to the mill and adapted to deliver the tailings to the drum at any predetermined distance from the inlet end of the drinn.

The present invention is designed yfor the purpose of speeding up production Portland cement and other inely ground material produced Irom rock, ore., etc., or relatively large masses oi' other material, by treatment in a novel manner during the reducing process in a. tube mill which may or may not be provided with compartments. Means are provided to return the pa tly linished material to any desired section or' the tube, or to any particular compartment thereoi2 to permit nishing oi the material in tile most ellieient manner.

By the employment of the present invention te return the tailings or to add other materials to the primary material being ground at such position lengthwise of the drum as to coinmingle it with material of substantially the same lineness, or ofthe same grindability, the cushioning effect upon the larger grinding balls acting initially upon the material is avoided and the rate of production oi' linely ground material is very considerably increased. Furthermore, greater uniformity in the product discharged from the delivery end of the drum is obtained.

The construction illustrated in Fig. 1 comprises a cylindrical metallic drum 1 having its ends abutting against heads 2 and 3 Which are provided respectively With preferably integral h llow trunnions 4 and 5 which are mounted in suitable, preferably hollow, bearings G and 7 in standards 8 and 9. The ends ot the drum are secured to the heads, preferably by angle iron plates 10 and 11 which are Welded, riveted, bolted, or otherwise secured to the drum and to the head. rPhe driving gear 12, which is secured to the angle plates 1l and head 8, is actuated in the usual manner by a pinion (not shown) driven in any suitable manner as is usual in such constructions.

he hollow trunnion 4 provides an inlet through which the material to be ground may be introduced into the drum, and the hollow trunnion 5 provides an outlet through which the ground material is delivered from the drum.

A scoop 18, connected to the end ol the hollow inlet trunnion 4, and provided with a mouth 14 adapted to pass through a feed box 15, provides means for feedingl the material iif'o the drum. The material is discharged trom the outlet trunnion 5 into a box 1G from which it passes through a suitable conduit 17 to an elevator 18, or any other transport system, which delivers the ground material to the inlet 19 of an air separator ZO, preferably of the type disclosed in the patent to Gibson and Needham No. 1,346,015, July (i, 1920. l-lowever, the material may be delivered to any other type of separator or classilier having means 1er returning the tailings to the grinding mill.

As illustrated in the accompanying drawings the tailings pass irom the air separator 2O through a pipe 21 to a suitable conveyer operable to deliver the tailings to the drum at any desired predetermined distance from the inlet end of the drum. in the preferred construction the eonveyer comprises a tubular metallic conduit 22 having a series of ports spaced at desired distances longitudinally of the conduit. Inasmuch as the wall of the conduit may be subject to abrasion of the contents or' the drum, it desirably may be armored by a series of cylin-drical separate plates 24 secured to the wall of the conduit and provided With ports 25 coinciding with 4die ports 23.

ySuitable adjustable gates are provided :tor causing the material to be discharged from the conduit at any desired predetermined distance from the inlet end or" the drum. The particular form of gates illustrated in the accompanying drawings comprises cylindrical sleeves 26 adapted to lit snugly the exterior of the conduit Q2. The sleeves 26 are adjustable along the conduit 22 to control the flou' of material out oithe ports 23. The ends ot the conduit 22 may be supported in any suitable manner, as, for example, by spiders 3() in the hollow inlet trunnion 4, and such other spiders as may be required, located at suitable distances apart longitudinally of the drum. The drum is provided with a usual lining 31 Which may, if desired, be provided with ribs 32. An annular wear plate 33 is provided at the inlet end of the drum, and the discharge end of the drum provided With a preferably slotted screen diaphragm 34, the periphery of which engages the drum 1 and the 'lace of which abuts against the lining 31.

ln the operation of the machine the material to be ground is fed into the box l5 from which it is scooped up by the scoop 13 and fed into the mill through the hollow trunnion 4. It is subjected to the grinding action of the usual grinding members, such as balls, pebbles, rods, etc., and the ground material passes through the screen diaphragm, which serves to prevent discharge of the grinding members, thence passes through the drum to the box or hopper 16 from which it passes through the conduit 17 to the elevator, or other suitable conveyor.

The material is discharged from the elevator into the inlet 19 of the separator or other Y classifier 20 and the finely ground material is duit to rotate therewith, as illustrated, or

may be driven by a separate source of power, as will be readily understood. By securing the screw or spirals to the wall of the conduit the drum, conduit and screw are rotated in unison, thereby avoiding the necessity of providing additional power for driving the screw, and thus reducing t-he expense or" operation of the machine.

Any of the sleeves 26 may be adjusted to cause the tailings to be delivered at a desired distance from the intake end of the grinding drum, so that the tailings discharged into the drum will be of substantially the same degree of tineness or grindability as t-he other material which is being treated within the drum at the position at which the tailings are added to it, thereby avoiding the cushioning eliect of the tailings which otherwise would be produced if delivered into the drum at the intake end thereof.

Obviously the conduit 23 may terminate at any desired point within the drum and the material delivered either from the end of the conduit or through an open port intermediate of its length. In such case the free end of the conduit would, of course, be supported upon a suitable spider.

The position at which it is desirable to introduce the tailings into the drum may be dependent upon the character of the material being ground and in the assembling of the mill a proper gate or sleeve may be slidably adjusted or removed to permit the material to be discharged at the desired distance from the inlet end of the drum.

By reason of the present invention, therefore, a construction is provided which can be readily adapted to rapid grinding of different materials.

The invention is illustrated in Fig. 4 of the drawings as ap lied to a compartment tube mill, n one Jfibrm, the drum comprises a main cylindrical portion 37 and a preferably enlarged initial section 38 having a tapered port-ion 39 merging into the main portion 37 of t-he drum. The drum is secured to heads having integral trunnions 40 and 41, of the character above described, providing respectively an inlet for the material to be ground and an outlet for the ground material. The trunnions are mounted respectively in bearings upon :standards 42 and 43 and t-he drum is rot-ated by a gear 44 secured to the main portion of the drum in the manner heretofore described. Y

A screen diaphragm, or preferably screen diaphragms 45 and 46 serve to separate the enlarged initial grinding compartment 47 from the chamber of the main portion 37 ot the drum. One or more screen diaphragins, or pairs of screen diaphragms 48, divide the chamber of the main drum into a series of compartments 49 and 50, etc.

Large grinding members, such as balls 5l, are provided in the lirst or initial grinding compartment, while progressively smaller balls 52 and 53, etc., are provided in the succeeding compartments 49 and 50, etc., of the mill. The material to be ground is fed into a box 54 from which it is carried by the usual scoop 55 secured to the hollow trunnion 40 `and delivered through the hollow trunnion into the initial grinding compartment of the mill where it is acted upon by the large grinding members 5l. The material passes from this compartment through the screen diaphragms 45 and 46 into the next compartment, where it is acted upon by the smaller grinding members 52, and thence through the screen diaphrgams 48 to the compartment 50 containing the still smaller balls 53. The material is delivered from the compartment 50 through a screen diaphragm 56 and discharged through the tubular trunnion 47 into a box or hopper 57 having a conduit 58 leading to an elevator 59, or other conveyer.

The elevator 59 discharges the material into the inlet 60 of an air separator or other classifier 6l from which the tine material is delivered through the outlet 62 and the tailings are returned to the mill through a chute 63. Any other desired means niav be employed to handle and return the material after it has passed through the mill during and after the classifying process. The lower end of the chute 63 communicates with a tubular conduit 64 having at intervals ports which are provided with gates. such as adjustable and detachable sleeves 66 of the character above specified. Any suitable number of ports with gates may be provided and the sleeves or gates may be slid longitudinally upon the conduit or removed therefrom to provide an open port, such as a port 67 for delivering the tailings at anv desired predetermined distance from the inlet end of any compartment. Preferably the material is not delivered to the initial grinding con'ipartment and the end ofthe conduit 64 may, therefore, be mounted in the diaphragms 45 and 46.

The diaphragm or diaphragms 48 may be placed at any suitable distance from the intake end of the main portion of the drum to divide the same into compartments of such suitable length as may be required to produce the desired grinding action.

A screw or spiral Hight 68, which extends longitudinally of the conduit 64, and which preferably is rigidly secured therein in the manner previously described, may be employed to cause the tailings to` travel longitudinally of the conduit. In this construction, 5 as in the construction previouslv described, the conduit G6 extends axially through the hollow outlet trunnion l? and is rigidly secured thereto by a. spider G9.

in Fig. 5 a modiiied construction is shown in which the drum 70 illustrated is, and may be similar to, that shown in Fig. l, and is similarly mounted and actuated. l'n this construction, however, the tubular conduit 7l is mounted at both ends in a spider 72 in the tubular inlet trunnion 73 and outlet trunnion 7l. A screw 75 serves to deliver the material from the feed box 76 through the tnbular inlet trunnion T3 to the drum, the material being delivered from the drum through the tubular outlet trunnion 7l. ln this construction the c lindrical conduit 7l which is irovided with a longitudinal series or ports e 4, with (.ietachable or adiustable sleeves or 78 therefor, is provided with a screw T9 .inlet end of the drum through a suitable hopper 80, a chute 8l leadingto the conduit 7l, so that in this construction the tailings, or other material, are introduced into the conduit Il at the inlet end of the drum and travel in the same direction as the direction of movement of the material being ground.

In this construction, as in the constructions previously described, any one of the gates may be opened or removed to permit the delivery of the tailings, or other material, into the drum at a desired distance from the inlet end thereof for the purposes heretofore described.

It is to be understood that the embodiments of the invention disclosed herein are o an illustrative character, and are not restrictive, and that the invention may be apjlied to other types or" tube, ball, or rod mills to which it may be applicable.

Having' thus described the invention, what is claimed as new, and desired to be secured o i Aettore Patent, is:

.ing drum having hollow trunnions at io-.idiiig respectively an inlet tor e mau-irial to be rrronnd and an outlet for l material, means for feedng the drum through said inlet means for introducing f including' a conveyer er than the hollow trunu j concentrically through one ho1 runnions into and longitudio said drum, and having means for the material into the drum at a predetermined distance from the inlet end of the drum.

2. A tube mill comprising a rotatable grinding drinn having hollow trunnions at its ends providing respectively an inlet for the material to be ground and an outlet for the ground material, means for feeding the material into the drum through said inlet trunnion, auxiliary means for introducing material into .said drum including a conveyer, extending through one of said hollow trunnions into and longitudinally of said drum, and having a plurality of means selectively operable to deliver the material from said conveyor to said drum at different predetermined distances trom the inlet end of said drum.

3. A tube mill comprising a rotatable grinding drum having hollow trunnions at its ends providing respectively an inlet for the material "o be ground and an outlet for the ground material, means for feeding the material into the drum through said inlet trunnion, auxiliary means for introducing material into said drum including an armored tubular conveyer, extending concentrically through one ot said hollow trunnions into and longitudinal y of said drum and rotata ble therewih, and having a plurality of means selectively operable to deliver the ma- A.Proz-n said conveyer to said drum at i end of said drum.

Li. A tube mill comprising a rotatable grinding drum having` hollow trunnions at its ends providing respectively an inlet for the material to be ground and an outlet for the ground material, means for eedlng the T:ntcrial into the drum through said inlet trnnnion, auxiliary means for introducing material into said drum including` a tubular conduit extending through one of said hollow trunnions into and longitudinally of said drinn and provided with a screw for causing the material to travel therethrough and with a plurality of ports, and adjustable gates for said ports selectively operable to deliver the material Jfrom said conduit to said drum at different predetermined distances from the inlet end of said drum.

A. tube mill comprising a rotatable rinding drum having hollow trunnions at ts ends providing respectively an inlet for he material to be ground and an outlet for the ground material, means for feeding the material into the drum through said Yinlet trunnion, auxiliary means for introducing material into said drum including a tubular conduit extendin concentrically through one of said trunnions into and longitudinally of said drum and connected to and rotatable with said drum, a screw extending longitudinally of said conduit and rotatable therewith, said conduit being provided with a plurality ot ports and adjustable gates for said ports selectively operable to deliver the material from said conduit to said drum at different Ofc ; predetermined distances from the` predetermined distances from the inlet end of said drum.

6. A tube mill comprising a rotatable grinding drum having hollow trunnions at its ends providing respectively an inlet for the material to be ground and an outlet for the ground material, means for feeding the material into the drum through said inlet trunnion, means dividing said drum into a plurality of compartments, auxiliary means for introducing material into said drum ineluding a tubular conduit extending longitudinally ot said drum and concentrically through one of said trunnions and said screening means, said conduit being provided with a plurality of ports and adjustable gates for said ports selectively operable to deliver material from said conduit to a selected compartment at a predetermined distance from the end of such compartment.

7. A tube mill comprising a rotatable grinding drum having hollow trunnions at its ends providing respectively an inlet for the material to be ground and an outlet tor the ground material, means for 'feeding the ma terial into the drum through said inlet trunnion, screen diaphragme extending transversely of the drum dividing the same into a plurality of compartments, auxiliary means for introducing material into the drum prising a tubular conduit extending concentrically through one of said hollow trunni ons and also concentrically through said screen diaphragms and secured thereto, means operable by the rotation of the drum to cause the material to travel longitudinally of said cenduit, said conduit having a longitudinal. series of ports, sleeve gates for said ports slidably and adjustably mounted on said conduit and respectively operable to discharge the material into a. selected compartment at predetermined distances from the inlet end of said compartment.

8. A tube mill comprising a rotatable grinding drum having hollow trunnions at its ends providing respectively an inlet for the material to be ground and an outlet for the ground material, means for feeding the material into the drum through said inlet trunnion, a tubular conduit extending concentrically through the delivery trunnion into and longitudinally of the drum and having a series ot ports, a separator for the ground material discharged from the outlet trunnion, means for returning the tailings from said separator to said conduit, means for causing the tailings to travel longitudinally of said conduit, and gates for said ports selectively operable to deliver the tailings from said conduit to the drum at diierent predetermined distances from the inlet end of the drum.

9. A tube mill comprising a. rotatable grinding drum having hollow trunnions at its ends providing respectively an inlet for the material to be ground and an outlet for the ground material, means for feeding the material into the drum through said inlet trunnion, screen diaphragms dividing the drum into a plurality of compartments, a tubular conduit extending concentrically through said delivery conduit and said diaphragms, and secured thereto, and provided with a longitudinal series of ports communicating with the respective compartments at intervals, a separator or other classifier for the ground material discharged from said outlet trunnien, means for returning the tailings from said separator or classifier to said conduit, a screw in said conduit operable to cause the tailings to travel longitudinally thereof, sleeves slidably adjustable on said conduit Jforming gates selectively operable to cause the material to be delivered to a selected compartment at a predetermined distance from the in let end thereof.

l0. A tube mill comprising a rotatable grinding drum having hollow trunnions at its ends providing respectively an inlet for the material to be ground and an outlet for the ground material, means for feeding the material into the drum through said inlet truu nien, screen diaphragms dividing the drum into a plurality of compartments, a tubular conduit extending concentrically through said deli Tery conduit and said diaphragme, an d secured thereto, and provided with a longitudin al series of ports communicating with the respective compartments at intervals, a separator for the ground material discharged t1 i said outlet trunnion, means for returning the tailings from said separator to said conduit, a screw tixedly secured in said conduit operable by the rotation of the conduit to cause the tailings to travel longitudinally thereof, and sleeves slidably adjustable upon said conduit forming gates for said ports selectively operable to cause the material to be delivered to a selected compartment at a predetermined distance trom the inlet end thereof.

In testimony whereof, l have signed my name to this specification.

ARTHUR W. GATLIN. 

